When a dump truck releases its load through the tail gate, the tail gate which is usually hinged to the rear top end of the side walls of the box of the truck sways as the box lifts to dump its load. Because some materials stick to the surface of the box due to humidity or the nature of the material, it is common that the driver of the truck will advance the truck and quickly apply the brakes to impart a jerking motion to the box and to cause the heavy steel tail gate to swing and impact against the open rear end of the box to impart vibration to the box whereby to dislodge the stuck material. This is a very noisy procedure as, usually, several attempts are made before dislodging all the stuck material. Often, operators of trucks will routinely cause the rear gate to impact the box when dumping a load without verifying if material is stuck or not to the box. This noise is undesirable. A further problem with the tail gates of the boxes of dump trucks is that they often do not completely seal the box due to the fact that it is in metal-to-metal contact with the box and the fit is not perfect. Also, because the tail gate is subjected to wear-and-tear, often cracks will form between the open rear edges of the box and the tail gate and this is not desirable when transporting fine material, such as sand, and particularly material which is polluting to the environment.
Another disadvantage of impacting the tail gate against the open rear edges of the box of the dump truck is that this subjects the tail gate and its connecting joints to wear-and-tear due to the impact and vibrations. Any weak weld joints or weld spots in the assembly of the tail gate are, therefore, subjected to these shocks and this often causes the welds to break or crack inhibiting corrosion.